The invention concerns a dosing system with a doctor element fashioned as a doctor rod, for the coating of material webs which are passed over at least one roll which is coordinated with the doctor element. The doctor element is accommodated in a bed supported by a holder. The holder is held on a wall of a mounting, which wall forms at the same time a bounding wall of a mouth channel for the coating mixture. The holder features on its end in on its side opposite the mounting wall a clamping or mounting surface. Such dosing systems are primarily used for the coating of webs of paper or cardboard.
Roll doctor rods are frequently used for the coating or dosing of coating mixture onto webs of paper or cardboard (refer, e.g., to DE 21 50 906). A roll carrying the paper web is generally coordinated with the doctor rod. Provisions often also are made such that the coating mixture serving the coating is fed from a chamber through a mouth whose bounding wall is the mounting wall on which the holder of the doctor bed accommodating the roll doctor rod is fixed.
In the flow path of the coating mixture from the mouth to the roll and roll doctor rod there are generally edges or cross-sectional changes of the flow channel created which may have an unfavorable effect on the coating. Such step is created notably also at the transition between said mounting wall and the holder of the doctor bed. The problem underlying the invention is to fashion the dosing system in such a way that minimally few edges and jumps, i.e., corresponding cross-sectional expansions or constrictions, occur in the flow path.